Twitter did not say how many accounts were actually affected versus how many people received the notice by mistake. But the company did give security tips in an earlier email it sent alerting users to a possible phishing scam.
The company recommended users check their browser's address bar when visiting the Twitter website to make sure the URL is indeed Twitter's legitimate site.
"Phishing sites often look just like Twitter, so check the URL before entering your login information!" the company said in the email.
It also recommended in its email that users not use services that claim to increase their followers and that users review their connections on their Twitter applications.
Read the full email below.
You'll need to create a new password for your Twitter account. You can select a new password at this link:
As always, you can also request a new password from our password-resend page: https://twitter.com/account/resend_password Please don't reuse your old password and be sure to choose a strong password (such as one with a combination of letters, numbers, and symbols).
In general, be sure to:
Always check that your browser's address bar is on a https://twitter.com website before entering your password. Phishing sites often look just like Twitter, so check the URL before entering your login information!
Avoid using websites or services that promise to get you lots of followers. These sites have been known to send spam updates and damage user accounts.
Review your approved connections on your Applications page at https://twitter.com/settings/applications. If you see any applications that you don't recognize, click the Revoke Access button.
For more information, visit our help page for hacked or compromised accounts.
The Twitter Team